The present invention relates generally to the high speed winding of filamentary material onto tubes or spools to form packages of filamentary material. More particularly, it relates to the handling of man-made filament yarn during the final stages of winding a full package.
The manufacture of man-made or synthetic filament yarns is typically achieved by extruding a molten polymer, such as polyester, polyamide, etc., through hole(s) in a spinneret and then cooling the filament(s) thus formed. Thereafter, the filaments may be gathered together to form a multi-filament yarn and, possibly after further treatment, are wound onto a tube so that a yarn package is formed.
Winding of the yarn is performed mechanically by winders which rotate one or more tubes to wind-up the yarn while traversing the yarn along the tube axis to achieve a uniform thickness of yarn being wound.
A doffing/donning operation (i.e., replacement of the yarn packages with empty tubes on the winder) is often performed manually by an operator who (i) severs the yarn, (ii) stops the rotary drive to the packages, (iii) replaces the packages with empty tubes, (iv) re-establishes the rotary drive between the winder drive head and the tubes, and (v) rethreads the yarn onto the empty tubes. Severing of the filamentary yarn is typically performed with scissors while the inlet of a suction or aspirator gun is held against the yarn at a location above the point of severing. Once the yarn is severed, the trailing end of the yarn is wound onto the yarn package, while the newly formed leading end of the yarn is sucked into the aspirator and fed to a waste collector. The suction gun is then placed onto a holder while the yarn packages are being replaced by empty tubes. When the empty tubes attain full speed, the operator manipulates the suction gun to attach the yarn to the rotating tubes so that this winding operation may begin.
In order to economize such winding operations, it has heretofore been proposed to mechanize the doffing and donning operations to a certain extent by providing a mechanism which automatically severs, aspirates and rethreads the yarn. Exemplary of proposed mechanisms of that type are the disclosures in U.S. Pat. No. 4,023,741 issued to Schar on May 17, 1977; U.S. Pat. No. 4,052,017 issued to Schar on Oct. 4, 1977; U.S. Pat. No. 4,108,388 issued to Schar on Aug. 22, 1978; and U.S. Pat. No. 4,496,109 issued on Jan. 29, 1985 from application Ser. No. 06/499,005, a division of application Ser. No. 06/258,309 filed Apr. 28, 1981, now abandoned.
In the Schar '388 patent a filament handler is arranged to travel along a row of winders to sequentially service the winders. The winders are of the type upon which a single bobbin is being wound at a given time. The filament handler comprises a cutter/aspirator unit which approaches the filament in a direction parallel to the axis of rotation of the bobbin, i.e., within the plane of oscillation of the filament. The cutter severs the filament which is immediately aspirated to waste. After the bobbins have been replaced, the cutter/aspirator unit is rotated about an axis disposed parallel to the bobbin axis so as to transfer the filament downwardly for being "thrown" onto the new bobbin.
Such a mechanism involves certain problems, including the need to properly align the cutter/aspirator unit with the filament every time that the unit arrives at a winding station. In that regard, it will be appreciated that even a relatively small amount of misalignment between the cutter/aspirator unit and the filament is sufficient to prevent a proper cutting of the filament from being achieved.
A further problem relates to the difficulty in adapting such a mechanism to winders of the type which simultaneously wind a plurality of filaments onto coaxially rotating bobbins. That is, it is difficult for the mechanism to cut and aspirate a plurality of filaments and then transfer the filaments onto respective bobbins.
The above problems have been overcome by a mechanism proposed in the above-mentioned application Ser. No. 06/258,309. In that mechanism, each winder is provided with its own filament-handling mechanism. The mechanism is constrained to move along a fixed path which assures that there will occur proper alignment between the cutter/aspirator unit and the filament(s). The cutter/aspirator unit moves parallel to the bobbin axis to cut and aspirate a plurality of filaments. However, the filaments are transferred downwardly for a "throw-on" step by separate arms which move vertically relative to the cutter/aspirator unit. The provision of transfer arms for acting upon respective filaments enables the filaments to be thrown onto the proper bobbin. Such an arrangement involves two relatively moving members, i.e., the cutter/aspirator unit and the transfer arms, whereas it may be desirable to reduce the number of relatively moving parts.
It is also desirable to employ a stiff tube through which the filamentary material is exhausted to waste in order to assure that proper engative pressures and a smooth travel path are maintainted in the tube. The use of flexible tubes may lead to the formation of bends or curves which are too abrupt to ensure proper transport of the filamentary material.
It is, therefore, an object of the present invention to provide a novel apparatus for aspirating filamentary material to waste.
Another object is to provide such an apparatus in which enables filamentary material to be aspirated by means of a downwardly traveling aspirator which communicates with a stiff tube.
A further object is to provide such an apparatus in which a plurality of filamentary materials can be simultaneously aspirated.
An additional object is to provide such an apparatus which minimizes the number of components.